August 2010 - Boost-users - lists.preview.boost.org

Fwd: Some trouble using mutexes
by Ernest Galbrun 30 Aug '10

30 Aug '10

Ok, thank you for your reply, I have been away for a week and I am back to work, with this problem still preventing my program to work fine. To answer your question, I have only one Robot in my project (for now) and the io_service is a Robot member. I now get why the active_count goes negative when the count goes up, but now I can't figure how it can ever be incremented twice. When debugging, I see the active_count being either 0, -2147483648, OR -2147483647. In fact, even when the active_count is not ==0, the lock() call returns instantly. Any clue ? Ernest Galbrun. > > Ernest Galbrun wrote: > > I would be really grateful if someone could give me a hint about what I > am > > doing wrong with the mutex and thread class (I am using boost 1.43, on > > windows XP running visual c++ 2010, the library has been built using the > > bjam utility). > > > > I have a main thread that creates an object of class robot : > > > > class Robot > > { > > private: > > boost::mutex tcpLock; > > boost::thread continuousThread; > > ... > > } > > > > Robot k3; > > > > this thread launches a thread that makes continuous calls to a member > > function of the robot. Since this function uses network ressources, I > want > > it to be safe so i use a lock The function called is the only function in > my > > program that uses this lock : > > > > int Robot::sendMsg(string msg, int n, vector<string>* answer) > > { > > tcpLock.lock(); > > (do stuff with the tcp io service) > > tcpLock.unlock(); > > return 0; > > } > > > > Of course, I also call this function from the main thread. > > > > And I have disruptive behavior, which I don't understand. > > Do you have multiple Robots? Is the io_service shared between them? > > > When debugging, I > > see that the 'active_count' of the tcpLock object stays negative or ==0, > > which seem absolutely wrong to me, but I don't understand how it could > ever > > be anything other than 0 or 1. > > > > The implementation indicates that the mutex is locked with the > high-order bit, which means that a locked mutex will have > a negative active count. > > In Christ, > Steven Watanabe >

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boost transfer pointers by serialize
by Jack Bryan 29 Aug '10

29 Aug '10

Dear All, I need to transfer some pointers from one process to another process on Open MPI cluster. These pointers are members of a class. They are like: class myClass{double *;int *;double**; } When I use serialize in boost , I got errors: /boost/serialization/access.hpp:118: error: request for member âserializeâ in âtâ, which is of non-class type âdoubleâ Any help is appreciated. JACK Aug. 29 2010

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boost thread - bug pthread
by Kraus Philipp 29 Aug '10

29 Aug '10

Hi, I'm writing a multithread application and I test my program with valgrind. I create a thread group and valgrind shows this message: ==4608== Thread #1: Bug in libpthread: recursive write lock granted on mutex/wrlock which does not support recursion ==4608== at 0x503FC: pthread_cond_wait* (hg_intercepts.c:653) ==4608== by 0x19C3B7: boost::thread::join() (in libboost_thread.dylib) ==4608== by 0x15D8C: boost::thread_group::join_all() (in ./main) I use Boost 1.44 on OSX 10.5. How can I solve this "Bug"? Thanks Phil

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string algo - documentation bug?
by mafeusek＠gmail.com 29 Aug '10

29 Aug '10

Hallo Group Members. in http://www.boost.org/doc/libs/1_44_0/doc/html/string_algo/concept.html I can read: * Function Finder. Finder can be any function object. That is, any ordinary function with the required signature can be used as well. However, such a function can be used only for a specific iterator type. boost::iterator_range<std::string> simple_finder( std::string::const_iterator Begin, std::string::const_iterator End ) { return boost::make_range( Begin, End ); } but following code does not compile: #include <iostream> #include <string> #include <boost/algorithm/string.hpp> #include <boost/range.hpp> int main(int argc, char *argv[]) { boost::iterator_range<std::string> dd; return 0; } As I understand, I need to put iterator as template parameter to iterator_range, thus: #include <iostream> #include <string> #include <boost/algorithm/string.hpp> #include <boost/range.hpp> /* boost::iterator_range<std::string> simple_finder( std::string::const_iterator Begin, std::string::const_iterator End ) { return boost::make_range( Begin, End ); } */ int main(int argc, char *argv[]) { boost::iterator_range<std::string::iterator> dd; return 0; } compiles ok. Is it documentation bug? best regards, Pawel

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Any stream class for C standard FILE * streams ?
by Timothy Madden 29 Aug '10

29 Aug '10

Hello Is there a stream class in boost that would use a C standard FILE * stream as the buffer ? Thank you, Timothy Madden

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Multiple link errors when using boost 1.44 boost::filesystem and gcc 4.1.2 on CentOS 5.5
by Potato Soup 29 Aug '10

29 Aug '10

I have installed gcc 4.1.2 (from Cent OS 5.5 repos), boost 1.44, and built all the libraries. I am able to link to all other libraries I try. As soon as I so much as add the include for boost::filesystem, and attempt to build my single .cpp file, I get the following errors: In function `__static_initialization_and_destruction_0(int, int)': testbuild.cpp:(.text+0xfa): undefined reference to `boost::system::generic_category()' testbuild.cpp:(.text+0x106): undefined reference to `boost::system::generic_category()' testbuild.cpp:(.text+0x112): undefined reference to `boost::system::system_category()' collect2: ld returned 1 exit status The linking stage fails and despite hours of googling I see no clear solution. I would be grateful for any advice on how to move past this, as it's the only thing holding me back from developing with boost. To be clear again, simply including <boost/filesystem.hpp> is enough to cause this when performing a link against libboost_filesystem.a.

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boost serialize error
by Jack Bryan 29 Aug '10

29 Aug '10

Dear All: I am trying to use boost (1.43) serialize to transfer data. But I got errors: ---------------------------------------------------------------- path/boost_1_43_0/boost/config/stdlib/libstdcpp3.hpp:40:1: warning: "BOOST_HAS_THREADS" redefined<command line>:1:1: warning: this is the location of the previous definitionpath/boost_1_43_0/boost/serialization/access.hpp: In static member function âstatic void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = int*]â:path/boost_1_43_0/boost/serialization/serialization.hpp:74: instantiated from âvoid boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = int*]âpath/boost_1_43_0/boost/serialization/serialization.hpp:133: instantiated from âvoid boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = int*]âpath/boost_1_43_0/boost/archive/detail/iserializer.hpp:182: instantiated from âvoid boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::mpi::packed_iarchive, T = int*]â myProg.cpp:413: instantiated from herepath/boost_1_43_0/boost/serialization/access.hpp:118: error: request for member âserializeâ in âtâ, which is of non-class type âint*âpath/boost_1_43_0/boost/serialization/access.hpp: In static member function âstatic void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = double]â:path/boost_1_43_0/boost/serialization/serialization.hpp:74: instantiated from âvoid boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = double]âpath/boost_1_43_0/boost/serialization/serialization.hpp:133: instantiated from âvoid boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = double]âpath/boost_1_43_0/boost/archive/detail/iserializer.hpp:182: instantiated from âvoid boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::mpi::packed_iarchive, T = double]â myProg.cpp:413: instantiated from herepath/boost_1_43_0/boost/serialization/access.hpp:118: error: request for member âserializeâ in âtâ, which is of non-class type âdoubleâpath/boost_1_43_0/boost/serialization/access.hpp: In static member function âstatic void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_oarchive, T = int*]â:path/boost_1_43_0/boost/serialization/serialization.hpp:74: instantiated from âvoid boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_oarchive, T = int*]âpath/boost_1_43_0/boost/serialization/serialization.hpp:133: instantiated from âvoid boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_oarchive, T = int*]âpath/boost_1_43_0/boost/archive/detail/oserializer.hpp:148: instantiated from âvoid boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::mpi::packed_oarchive, T = int*]â ---------------------------------------------------------------- It does not indicate the line number of my program with errors. The 413 is the last line of myProg.cpp. What is the meaning of "request for member serialize in t, which is of non-class type double" ? Any help is appreciated. Jack Aug. 28 2010

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Fwd: Bundled properties for GraphProperties
by Saeed Nari 29 Aug '10

29 Aug '10

Hi all, I wonder if I can use a user defined class (bundled property) as a GraphProperty. The documentation just says about vertex and edge properties. Actually I could compile the below line with no errors: typedef adjacency_list<listS, vecS, directedS, vClass, eClass, gClass> Graph; vClass, eClass and gClass are my own classes. I don't know how to access the members from gClass anyway. Graph g; Vertex v; Edge e; g[v].vMember and g[e].eMember work fine. But I get error for g.gMember. Thanks Saeed

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Is Boost-CMake Dead or Alive?
by Michael Jackson 28 Aug '10

28 Aug '10

http://ryppl.org/news/ So the boost-svn tracking is now hosted at Github. Ok. If you read farther down the page then it looks like Boost-CMake really _is_ going to be resurrected in the future? Is there any current activity with respect to Boost and git and cmake? I am so confused. I was going to take over for Troy S. in getting Boost-CMake ready after each release but if there is "Official" work doing this then I am not going to waste me time. Clarifications would be wonderful at this point. Thanks Mike Jackson

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Any class for a buffer or temporary file ?
by Timothy Madden 28 Aug '10

28 Aug '10

Hello Is there a class or stream class in boost to implement a buffer that will use memory storage fro small data sizes, and disk storage in temporary files for large data sizes ? Or is there a (random-access) file stream class to open some unnamed or temporary file that will automatically be deleted after closing ? Thank you, Timothy Madden

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